“I’m wondering if you’ve had a problem with Eastern Filbert Blight on your Corylus avellana ‘Contorta.’ You may be aware that Ken and I removed the specimen from the Haddam Extension Center for this reason.” -Robert Mirer
Let’s Put off the Peas
We received a comment from friend and master gardener Robert Mirer that caused us to change our scheduled topic for this week. We were going to talk about planting peas on St. Patrick’s Day, but his question about our Corylus avellana ‘Contorta’ got the madman thinking. It is too cold to even consider peas but it is a perfect time to revisit inspection of the landscape; starting with our Harry Lauder’s Walking Stick.
Harry Lauder’s Walking Stick
We discovered this fascinating plant very early in our gardening career. I saw a picture of the plant in a catalog and had to have it – I actually ordered three, two for me and one for my mother. I had a difficult time convincing the madman that it was worthy of inclusion in our landscape even though it had no fruit. “If you can’t eat it, why grow it?” He always said. (Although he has mellowed, he still fights every rose I want to acquire). In time the madman came to like the twisted branches of the plant, especially after he learned how it got its common name.
C. avellana ‘Contorta’ was discovered growing in an English hedgerow in the mid-1800s by Victorian gardener Canon Ellacombe. The madman says that Mr. Ellacombe blew it – since he discovered the plant he should have called it a Canon plant or Ellacombe’s Spirals, alas that was not to be.
Who Was Harry Lauder?
The plant was named for Sir Harry Lauder. Who is Sir Harry Lauder, you ask? Well, glad you did. Sir Harry was a world renowned song-and-dance man who sang Scottish ballads on stages throughout the civilized world (calling him a vaudevillian does not do him justice). He always appeared in public in traditional Scottish dress and carried a trademark corkscrewed walking stick. What better way to honor the man Sir Winston Churchill called “Scotland’s greatest ever ambassador”?
So we had a couple of these walking sticks. One was planted in a wet area (an early mistake) and did not last long. The other received a spot of honor – it was planted just outside the common entry to our house. All fine was for a few years. The plant flourished. A robin even chose this as a fine place to raise her young one spring.
The Madman Finds Strange Spots on Harry’s Branches
Then one day the madman noticed some strange lesions in the bark. He had no idea what they were, but he knew they weren’t right. Can you imagine discovering this before Google? We consulted a friend who was an arborist for the State. He came over to look at the lesions and said, “I’ve never seen that before.” He told us it was a blight of some type, and pronounced the plant unsalvageable. Today we would have taken a branch to the county extension service at UConn for diagnosis – I’m sure they would come up with the same fate.
Anyway, by now the madman was rather fond ofthe plant and refused to accept this diagnosis.Although he didn’t realize it at the time, he started acting like aMaster Gardener and did the appropriate research. He headed to the library andreturned with an armful of reference books. He put his H.P. Lovecraft novelaside and began reading about C.avellana and its related species.
Harry’s Hidden Identity
“Do you realize it’s a filbert?” he asked overhis lemonade. I have to tell you the madman is allergic to nuts; luckily the C. avellana ‘Contorta’ does not produce any – it is simplya member of the hazelnut family. So what do filberts and hazelnuts have incommon? They are actually one and the same.
Hazelnuts are a staple in European baked goods.The peak time of harvest is around August 20, the feast day of St. Philibert, a French saint. The English version is Filbert and now everyonecalls these nuts filberts. But, what to do about our hurting Walking Stick?
A Fungus Called Anisogramma anomala
The madman discovered that C. avellana is not a native plant, and it is susceptibleto Eastern Filbert Blight, which is caused by a fungus called A. anomala.The lesions he had discovered on our Harry Lauder’s Walking Stick lookedexactly like the pictures in the book. The blight causes football shapedcancers on branches and main trunks. Over time they girdle the branch. Althoughfatal to all C.avellana, this disease affects butdoesn’t kill our native Corylus americana although it does affect some shootsand leaves. We cut off all of Harry’s diseased parts and hoped for the best.
The fungus primarily infects immature tissue onactively growing shoots. Initially there is no outward sign. By the time themadman noticed the cankers the disease had been cooking for at least a year anda half. As it turns out, we hadn’t cut back far enough and new cankers appeared.Eventually Harry died and was removed.
The Disease Triangle
Plant disease, either bacterial, viral or fungal, relies on three elements. Referred to as the Disease Triangle, all three must be present before disease occurs.
The first point of the triangle is the Host. In our case, Harry was the host. Integrated Pest Management (IPM) suggests the first key to prevention of disease is to plant resistant varieties. Since our native C. americana is tolerant of Eastern Filbert Blight, we could plant that variety. But the madman insists that the native variety can’t hold a candle, or a walking stick, to Harry. No spirals, no plant.
Second Point of DiseaseTriangle
The second point of our disease triangle is the pathogen itself. In this case, it was A. anomala, a fungus that spreads by spores. The spores reach the plant from water splash or a breeze. It probably was blown in on the wind, but it could also have arrived on our clothing or boots (we do a lot of hiking).
Finally, the last point on the disease triangle is favorable conditions. Like most fungus, A. anomala thrives in moist humid conditions. Therefore, a wet spring like we often have in Connecticut is right up this bad boy’s alley. Most fungus enters through damage in the plant. Not this one, it attacks new growth to quietly enter a plant when it is happily growing.
Trying to Fight Nature
But knowing all this doesn’t stop the madman. He has become quite fond of the twisted appearance of this plant – especially in winter. We have acquired several more and generally keep them in pots. The one that Rob was questioning (earlier photo) was recently planted in the area we call Edge of Forest. Yes, Rob, we worry about it.
The Madman is Doing His Bestfor Harry
We planted it in an area with good air flow,excellent drainage and we have invested in a nice umbrella for use during rainyperiods. We could start a regimen of spraying, but this seems like too muchtrouble and we don’t really like this option. Instead, we spend a lot of timeinspecting the plants and trying to keep each one healthy and happy.
We know that native varieties in our area are tolerant of the disease, so we aren’t harboring a disease that will harm native populations. We also know that there are no commercially grown C. avellana (most are grown in Oregon) in our area so we are not affecting local food crops.
Disease Resistant Varieties
In doing some research, I have discovered a couple of ornamental varieties that are resistant to the blight. One was developed in Europe and is called C. avellana “Red Majestic”. In addition to the contortion, this variety sports red leaves and purple branches. The other was developed at the University of Oregon, C. avellana “Red Dragon”-this variety seems to have more good traits than the “Red Majestic”. There is a third ornamental Corylus that has lacy burgundy leaves, but no contortion so I didn’t even look at that.
Not only did I find this plant, I found a local supplier. Broken Arrow Nursery, a wonderful nursery in Hamden, has Red Dragon in stock and one of these plants has my name on it. As an aside, if you don’t know Broken Arrow Nursery, treat yourself and pay them a visit, as they say on their website, they are “growers of rare and unusual plants.”
The Plant in Haddam
But back to the plant you and Ken removed at the center. On our first day of Master Gardening class back in 2011 we noticed a large Harry Lauder’s Walking Stick by the entrance to the Haddam Extension Center. The madman looked at me and said “I wonder if that has the blight.” There was no sign of it at first. But one day, walking into a meeting of the Focus Garden Group, he noticed some football shaped cankers. Then life got in the way and we didn’t spend a lot of time in Haddam. In fact, when we went down to help with the first class this year, we noticed that the plant was gone.
So why bother telling this story? It highlights the importance of constant scouting. Not just vegetable plants during the growing season, but also landscape plants during all seasons. It also highlights the importance of planting the right plant in the right place. The madman knows the rules, but knowing the rules he often likes to bend them. As long as he knows the consequences, I just shake my head, back off and let him go.
And, I know when it’s time for cocoa. Hope to see many of you at the CMGA Symposium.